other than sight radius, some (SOME special ) barrels are slightly tapered internally for accuracy, some are slightly "choked" (for lack of a better word) The tapered ones are tighter at the muzzle than the breech. They are usually made for skirted bullets that obturate to better fill the grooves. (Like the Minnie ball projectile) High grade .22 LR target barrels are also made like this. The "choked" barrels are also used (in smaller diameters) in higher grade pellet target rifles.
If you are thinking of cutting off a $1,xxx.xx barrel, cut the breech end and re-breech it. Otherwise no worries.